1. Technical Field
The present disclosure relates generally to endoscopic surgical devices, and more particularly to bipolar electrosurgical devices for coagulation, cutting and micro-dissection of tissue.
2. Background Discussion
Neurosurgery is the surgical specialty that deals with the nervous system, generally the brain, spinal cord, and peripheral nerves. Surgery may be required in these regions due to tumors, traumatic injury, birth defects, cancer, aneurysms, and other complications. Depending on the condition and location within the body, different techniques are used to access the target region. In the 1980's, minimally invasive surgery techniques were pioneered and developed, and have since changed the standards for how many operations are performed. One of the largest benefits of minimally invasive surgery is that the patient experiences less operative trauma compared to an equivalent invasive procedure. Other benefits include less scaring, less blood loss, less risk of infection, faster recovery, and shorter hospital stay.
In the past, the base of the skull was one of the most challenging anatomic regions to access. In order to operate in this region, facial disarticulations and removal of the facial skeletons were necessary. Layers of bony, vascular, and neural structures were removed from the patient until the surgeons reached the target region, usually deep within the brain. This outside-in approach is very traumatic for the patient and the risk for impairing normal functions is extremely high.
In recent years, the use of minimally invasive techniques and devices has been applied to access the skull base region. This surgical technique is called the Endoscopic Endonasal Approach (EEA), and is used to remove tumors and lesions of the skull base and the top of the spine by directly operating through the nose and sinuses. Long, thin, highly sophisticated instruments are used to perform these surgeries. This inside-out approach using EEA eliminates the need to remove critical facial structures to reach tumors near the base of the brain.
One of the main concerns during surgical procedures is minimizing blood loss. One technique used to reduce or stop bleeding from small vessels in neurosurgical procedures is electrocautery. Electrocautery is the process of burning or destroying tissue using a metal probe heated by electric current. There are two types of electrocautery devices: monopolar and bipolar. Bipolar devices can better control and direct the electric field generated compared to monopolar devices, thus resulting in less adjacent tissue damage.
The currently available endoscopic bipolar electrosurgical devices lack certain functionality and precision that are desired for endoscopic surgical procedures. Most of the currently available endoscopic bipolar electrosurgical devices employ tweezers style forceps jaws with the use of a tubular body to force the jaws closed and rely on the natural spring restoring force of the tweezers to open the jaws. The first issue that arises from this design choice is that the closing point location of the forceps is not fixed axially. This complicates the perception and actuation of the closing point and can lead to the surgeon missing their intended target. The severity of this issue is amplified especially for neurosurgical procedures due to the high risk of damaging life critical adjacent tissue structures. The second issue that arises from the tweezers type design is that the device cannot reliably perform precise and controlled micro-dissection. Micro-dissection is the procedure surgeons use with the opening motion of the forceps to spread tissue apart in a controlled manner.